Spherical tire for a self-propelled vehicle

Abstract

A support assembly for a vehicle includes at least two spherical tires travelling on a road surface and rotating relative to the road surface and the vehicle and a drive system magnetically driving rotation of the tires relative to the drive system itself such that no portion of the drive system physically contacts the tires or the road surface. The tires each have an outer tread layer comprising a material having a first stiffness when dry and a second stiffness when wet, the first stiffness being greater than the second stiffness.

What is claimed: 
     
         1 . A support assembly for a vehicle comprising:
 at least two spherical tires travelling on a road surface and rotating relative to the road surface and the vehicle; the tires having an outer tread layer comprising a material having a first stiffness when dry and a second stiffness when wet, the first stiffness being greater than the second stiffness; and   a drive system magnetically driving rotation of the tires relative to the drive system itself such that no portion of the drive system physically contacts the tires or the road surface, the drive system magnetically levitates the vehicle a first predetermined distance from the tires, at least one of the spherical tires comprising:   an outer tread layer comprising a filler selected from the group consisting of carbon black and silica and a copolymer, the copolymer comprising: a polymeric backbone chain derived from a monomer comprising at least one conjugated diene monomer and, optionally, at least one vinyl aromatic monomer; and polymeric sidechains bonded to the backbone chain, the sidechains comprising a polymer capable of exhibiting a lower critical solution temperature (LCST) and, optionally, at least one additional diene based elastomer.   
     
     
         2 . The support assembly as set forth in  claim 1  wherein the drive system magnetically levitates itself a second predetermined distance from an inner surface of the tires. 
     
     
         3 . The support assembly as set forth in  claim 2  wherein the tires are closed sphere having and interior space completely separate from external environment. 
     
     
         4 . The support assembly as set forth in  claim 3  wherein the drive system comprises a first magnetically passive part and a second magnetically active part. 
     
     
         5 . The support assembly as set forth in  claim 4  wherein the first part generates only a constant magnetic field. 
     
     
         6 . The support assembly as set forth in  claim 5  wherein the second part generates a constant magnetic field and a variable magnetic field. 
     
     
         7 . The support assembly as set forth in  claim 6  wherein the drive system maintains the vehicle at a substantially constant orientation relative to the drive system. 
     
     
         8 . The support assembly as set forth in  claim 7  wherein the tires include a plurality off layers. 
     
     
         9 . The support assembly as set forth in  claim 8  wherein one of the plurality of layers mechanically supports a portion of a load determined by the vehicle. 
     
     
         10 . The support assembly as set forth in  claim 9  wherein one of the plurality of layers comprises a tread for generating traction between the tires and the road surface. 
     
     
         11 . The support assembly as set forth in  claim 10  wherein one of the plurality of layers comprises an elastomeric layer for damping vibration caused by the tires traveling over the road surface.